Structural highlights
Function[KINH_HUMAN] Microtubule-dependent motor required for normal distribution of mitochondria and lysosomes (By similarity). [F2Z5B2_PIG] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain.[RuleBase:RU003505] [TBA1B_PIG] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. Publication Abstract from PubMedMicrotubule-based transport by the kinesin motors, powered by ATP hydrolysis, is essential for a wide range of vital processes in eukaryotes. We obtained insight into this process by developing atomic models for no-nucleotide and ATP states of the monomeric kinesin motor domain on microtubules from cryo-EM reconstructions at 5-6A resolution. By comparing these models with existing X-ray structures of ADP-bound kinesin, we infer a mechanistic scheme in which microtubule attachment, mediated by a universally conserved 'linchpin' residue in kinesin (N255), triggers a clamshell opening of the nucleotide cleft and accompanying release of ADP. Binding of ATP re-closes the cleft in a manner that tightly couples to translocation of cargo, via kinesin's 'neck linker' element. These structural transitions are reminiscent of the analogous nucleotide-exchange steps in the myosin and F1-ATPase motors, and inform how the two heads of a kinesin dimer 'gate' each other to promote coordinated stepping along microtubules. High-resolution structures of kinesin on microtubules provide a basis for nucleotide-gated force generation.,Shang Z, Zhou K, Xu C, Csencsits R, Cochran JC, Sindelar CV Elife. 2014 Nov 21;3. doi: 10.7554/eLife.04686. PMID:25415053[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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